Silicates, sulfates, aluminates, etc. Look up "Portland cement". The Portlandite that they're talking about is only a very small part. The cement-making process requires very high temperatures to create the calcium silicates and such that are actually hard. Limestone is not hard enough or strong enough for heavy construction. Pretty white facings, yes. Structural strength, no.

Too bad they don't teach American History in school any more.

The Electoral College was a compromise among those drafting the Constitution to provide more equal representation to the (very) small (sovereign) states, such as Rhode Island, to keep them from being totally overshadowed by the larger, more populous states such as New York or Virginia or Pennsylvania. Without this compromise, there would have been no acceptance of the Constitution, and hence, no Union. Remember, they were piecing together the United States from thirteen individual sovereign states, each with its own separate government.

Travel time had nothing to do with it, although it did provide that benefit. By the time anybody was coming from the Ohio Valley, the EC was a well established fact.

The entire timekeeping system for the world is based on the definition of 12:00:00 GMT (aka Zulu, aka UTC) as the time when the sun is directly overhead at the Greenwich Observatory in Greenwich, England. Hence Greenwich Mean Time. Arbitrary? Perhaps. But recognized by every standards body on the planet. History, my friend.

Anything beyond about 20 feet is essentially at infinity focus. What is lacking in cameras is depth perception. Try driving, or backing up, with one eye covered (caution). It's surprisingly difficult to do confidently. Until they figure out how to do 3D cameras and displays in cars, they won't replace mirrors in functionality.

Or maybe just change our mind-set to do everything one hour earlier. There is nothing that requires our workday to begin at 9:00 am, so just adjust business hours. Granted, eight to four is not as catchy a song title, but hey...

Are these rear view cameras going to be 3D? Has anyone even considered the disadvantage of losing any depth perception to the flat, 2 dimensional presentation of a video screen? I have trouble imagining the difficulty this would present in a backing situation. With a mirror, you can get a sense of depth and perspective to judge distances. A camera would just give a flat, detached representation of what was there. And perspective would be dependent on the focal length of the lens, among other things.

One leg's the same.

And that was a good way to demonstrate you have no sense of humor.